Abstract
Purpose:
The prognosis of the exudative form of age-related macular degeneration has been largely improved with the use intravitreal injections of anti-VEGF. However, more than 10% of patients do not respond completely to the treatment, likely due to genetic predispositions, particular clinical forms or to tachyphylaxis. The aim of this study was to detect immune response induced by intravitreal injections of ranibizumab in exudative AMD patients.
Methods:
Blood samples were collected from exudative AMD patients with previous or no history of intravitreal injections of Ranibizumab in a same clinical setting. Specific immunization was proved using a combination of ELISA. A first ELISA was used to detect antibodies directed against the variable regions of ranibizumab. A second ELISA with abciximab (Reopro®, Elli Lilly) was used as a control antigen to detect false positive results, because abciximab shares with ranibizumab same constant regions.
Results:
Among 91 patients (28 men and 63 women, mean age 79) included in this study, 46 received more than 10 IVTs, 36 had received 10 IVTs or less and 9 were treatment naïve. Specific anti-ranibizumab IgGs were detected in 17.1% of patients previously treated with ranibizumab. Among patients with 10 or less previous IVT, immunization against Ranibizumab was detected in 4 of 36 patients (11.1%) whereas immunization was observed in 10 of 46 patients (21.7%) with more than 10 previous IVT (p=0.20). No immunization was detected among naive patients.
Conclusions:
These results suggest that immunization against ranibizumab could be commonly observed and may perhaps influence the clinical outcome of treatment. No correlation was observed between the level of immunization and ocular inflammation in the present study. Further clinical studies are needed to investigate the relationship between specific immunization to anti-VEGFs and resistance to these treatments.
Keywords: 412 age-related macular degeneration •
561 injection •
748 vascular endothelial growth factor